The present invention is primarily directed, but not limited to, heavy-duty vehicles such as lift trucks or the like. One of the inherent problems with equipment of this type is that it is possible for the operator to place the vehicle's automatic transmission in a gear opposite the direction of travel of the vehicle while the vehicle is in motion. In effect, the operator, by not making the effort required to apply the vehicle's brake to bring the vehicle to a halt prior to changing direction, is using the transmission itself to brake the vehicle. This invariably results in excessively rapid wear of the vehicle's transmission, thus greatly adding to maintenance expenses. It is desirable, therefore, to force the driver of such a vehicle to use the regular brake system to brake the vehicle prior to changing its direction.
Accordingly, it is an object of this invention to provide a means for preventing shifting of an automatic transmission while the vehicle is in motion.
It is a further object of this invention to provide a locking means for preventing the shifting of an automatic transmission between forward and reverse gears while the vehicle is in motion.
It is yet another object of the present invention to provide a mechanism of the type herein before outlined wherein the locking means can only be disengaged through the use of the vehicle's regular wheel brake system.